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Discussion Starter · #1 · (Edited)
How-To: Install Rostra Universal Lumbar Kit

Overview
This tutorial will describe how to install the Rostra Precision Controls Universal Lumbar Kit in the Cruze.

Part Number & Cost
Rostra 250-1752; $99 Retail

A group buy is currently available as of 01/20/15 to get the kit for $69 plus shipping:
http://www.cruzetalk.com/forum/9-ge...ostra-group-buy-cruze-lumbar-kit-drl-kit.html

Required Tools and Materials

  • T500 Torx bit. A high quality T50 worked for me but a T500 is a better fit and is made for a higher torque spec.
  • 10mm socket
  • Ratchet
  • Wire stripper
  • Terminal crimper
  • Utility knife with new blade
  • Roll of 16 gauge red wire
  • Roll of 16 gauge black wire
  • Two insulated 1/4" female slide-on connectors/terminals
  • One 1/4" stud ring terminal
  • One wire splice
  • Roll of fleece tape
  • Extra zipties

Procedure
Before I begin, I want to mention a few things. This will not be the only way to install this kit, but it is effective and modular. While installing this kit, you will see pictures that will look a tad different from what you will see with regard to the seat cover. When I bought my Cruze Eco, I had the seats upholstered with leather by a local shop that the dealer used, so taking apart the seat may be a different process for you. I will outline the process I took, and you will have to evaluate how your own seat cover is removed to determine how to get to the back of the seat.

To begin, you will need to access the rear of the seat. Slide the seat all the way forward. Using a T50 torx bit, you will need to remove the two bolts that hold down the seat rails. On my car, I had to get an impact wrench to get these off because they were on tight, so make sure you can loosen those bolts first before you do anything.

Once you get the bolts loosened, lift the rear of the seat, and the front should slide out. The front only hooks into the sheet metal; it isn't bolted down.

Disconnect the battery ground in the enigne bay.

In my particular car, I had to lift a flap that covered the lower part of the seat. After doing so, I noticed that the seat cover was held together using these wire fasteners.



I removed fasteners to allow me to slide the bottom part of the seat cover out of the way.




Once you've separated the seat covers, you will be able to see the wire mesh that holds the seat foam. You will need to slide the bladder between the spring mesh and the seat cushion. You can review Boraz's writeup to see how this was done on the OEM leather seats:

http://www.cruzetalk.com/forum/161-...how-add-power-lumbar-support.html#post1651074

Note: Boraz' writeup will look a bit different as he used the large bladder in his kit. The kit I recommend is the medium sized bladder according to the part number listed at the top of this tutorial.

Once you have the bladder installed, secure it with zipties. Be sure to position it where you want lower back support to be. If needed, sit in the passenger seat. I would recommend the position I chose below.



Following the second picture above, I cut the zipties and re-attached the bladder. The reason is the ziptie orientation. When you cut off the excess strip from the ziptie, a somewhat sharp end will protrude. The way I initially had it, the sharp end would protrude out toward the back of the seat. I was worried that if someone sat in the back and pressed their knees against the back of the seat, it could eventually cause a tear. Be mindful of this when you tie down the bladder.

I ran the hose for the bladder through the opening where the wiring harness goes through. While I did not show it in this picture, I wrapped the hose with fleece tape and also taped it together with the wiring harness.


Underneath the seat, I mounted the pump in the following location. Note: if you have a power seat, you will need to find a different place to mount the pump.


Remove the trim on the floor to the left of the seat. You will need to work your way forward from the back, lifting up on the back and then pulling rearward to get the part under the console out.

Next, we will make the wiring harness. Start with a strip of red and blue wire. Strip each end and crimp the slide-on connectors like so. To the left are the new wires, and to the right is the wiring harness that the kit comes with. Wrap the wire with fleece tape, and slide it through underneath the floor of the seat so it comes out as shown below.


With the floor trim removed, you will find a ground point. Cut the black wire according to the correct length to reach that ground point, strip the wire, crimp on the 1/4" ring terminal, remove the 10mm nut, place the wire over the stud, and re-tighten the nut.

Next, remove the fuse box cover right above where you were just working. You will need to detach the fuse box and pull it through the opening. To do this, there are two tabs at the top of the fuse box. Pull them toward each other with one hand, while using the other hand to push the fuse box from the back. You will have to reach behind the dash to do this.


Once you have the fuse box pulled back, it will be resting on two channels as shown below. Simply side it up.


To clear the opening, you will need to twist it to the left.


Flip the fuse box over. On the back, there is a black cover. Remove that cover.


Run your red wire to the back of the fuse box and cut the wire. Refer to the image below to see how long it needs to be. Splice into one of the 20A auxiliary circuits. The one I chose had a purple wire as shown below.


Reattach the black cover and reinstall the fuse box.

Reinstall the floor trim.

The next part will involve cutting a hole in the seat to mount the switch. Don't do what I did. I figured it would look good in the middle, which it does, but the reality is that right behind this point, there is some molded plastic (which doesn't appear to serve any purpose in my car), but made my job all that much more difficult. In short, verify what is behind where you will be cutting to ensure that you have the necessary clearance. Refer to the following images not as a recommended switch mounting point, but simply to show you how the switch is mounted. I repeat, do not use the location I used for mounting the switch.

I used the little plastic tab to outline where I was going to make the cut. Slowly and carefully using the utility knife, cut an outline of where the switch will be mounted. Alternately, you can use a pencil.



Slowly carve a deeper groove into the plastic. Be VERY careful not to push too hard, or the blade may slip and you'll end up leaving an unsightly grove in the plastic. Work slowly and patiently. Eventually, you will be able to push the blade clear through the plastic.

Finish cutting the piece out, then test fit the switch. Enlarge the mounting hole by shaving off more plastic as needed.


Connect the two female slide connectors to the male slide connectors in the kit's wiring harness and tuck them into the floor opening.
Connect the wiring harness to the pump and to the switch.
Connect the battery ground you should have disconnected earlier.
Test to make sure the kit works.
Ziptie the wiring to the underside of the seat to keep it tidy, but make sure to leave enough room for the seat to move forward and backward without pulling on the wire.
Slide the seat back into its latched position and reinstall the seat rail mounting bolts.
 

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Discussion Starter · #2 · (Edited)
So far, the kit is very effective. It provides more lumbar support than is needed, which is good considering it is adjustable. I have 2 hours worth of driving to do tomorrow, so I will report back on my impressions after that.
 

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no seat bolt tq #'s?

disappointed in you. :grin:

guessing the upholster dude really tightened down your seat, cuz mine was just blue loctite, that stuff is kids play.
 

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Are the seat mounting bolts a T50 or T500?
Seat belt anchors use the special T500 bit.
 

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Discussion Starter · #5 ·
A T50 fit in there just fine. I even went to the garage and double checked.

Torque spec for the bolts? Lol. "Good n tight." I'll update it if someone wants to look it up for me.

It must have been the reupholstering people that overtightened those bolts.
 

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Must have been the lack of ambition for not doing this in the first place. :)

Went out to the barn and retrieved both my T50 and T500 sockets.
The two bolts that hold the seat rails down at the rear are T500s. The T50 fits but does not fit as tight as the T500.

The T500 series appears to be designed for a higher torque rating.

Sockets used for comparison
-Snap-On FTX50C (T50)
-Snap-On FTX500 (T500)
 

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Discussion Starter · #7 ·
Must have been the lack of ambition for not doing this in the first place. :)

Went out to the barn and retrieved both my T50 and T500 sockets.
The two bolts that hold the seat rails down at the rear are T500s. The T50 fits but does not fit as tight as the T500.

The T500 series appears to be designed for a higher torque rating.

Sockets used for comparison
-Snap-On FTX50C (T50)
-Snap-On FTX500 (T500)
Thanks. I updated the tutorial. I have a feeling most people are going to just try the T50 as they may not be able to find a T500, but I've noted it as the more recommended option.
 

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Discussion Starter · #8 ·
I wanted to get some driving in before I provide a report on the lumbar kit. IMO, this was the only thing missing from my Cruze. I drove about 2.5 hours today over two trips, stopping only once to get gas. Normally, my lower back would be getting sore after about half an hour of driving and I'd have to arch my back to stretch it out a bit. Not the most comfortable thing to do on a long drive.

After each of these drives, I didn't notice any soreness whatsoever. I got out of the car and felt like I hadn't even been driving. For $70, this is, dollar for difference, one of the best things I've done to my Cruze. I strongly recommend it to anyone who has any lower back soreness. It is a fairly simple install and can be knocked out in one afternoon if you already have the materials.
 

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no seat bolt tq #'s?

disappointed in you. :grin:

guessing the upholster dude really tightened down your seat, cuz mine was just blue loctite, that stuff is kids play.
Only because I looked this up when removing the seats for the heated seat kit.
Front Seat Mounting Bolt 33 ft/lbs. With blue Loctite

It appears that the T500 may be the same as a T-47.

The T-47 is an odd size that comes up as a GM Specialty tool for a lot of google searches. It can be found at Sears individually. If someone want's to buy just one socket this may be worth trying. Otherwise a T-50 does work, provided you push down into the fastener. With a factory installed bolt I needed a 1/2" breaker bar to break it free. It had to be the Loctite.

Snap-On FTX500 T47 Torx Socket [78946] - $14.99 : Used Tool Sales and Tool Repair | East Coast Tools, Used Tool Sales and Tool Repair | East Coast Tools
 

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I installed this lumbar support from Rostra Group $69.95 plus shipping in my 2014 Cruze. It took approx 2 hr and that was taking my time.Comes with everything you need. Box included lumbar bladder, air pump, switch even plastic cable ties,hose and instructions. I have leather heated power seats and located switch just above the power seat switch. The difference is unbelievable !!! I have photos if needed.
 

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I installed this lumbar support from Rostra Group $69.95 plus shipping in my 2014 Cruze. It took approx 2 hr and that was taking my time.Comes with everything you need. Box included lumbar bladder, air pump, switch even plastic cable ties,hose and instructions. I have leather heated power seats and located switch just above the power seat switch. The difference is unbelievable !!! I have photos if needed.

Yes, pictures would be great, thanks!
 

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Discussion Starter · #13 ·
My pregnant wife has been driving my Cruze around on errands. She is a stay at home mom and I work from home full time. The other day we drove and I was in the passenger seat. She didn't realize how big of a difference the lumbar kit made and she started having some lower back pain.

Looks like I'm installing another lumbar kit soon.
 

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The second kit I received was close to this. Instead of wiring to the back of the fuse box, however, it had a "plug" that fits around a fuse so all I had to do was remove a 20 amp fuse (I used fuse #7, which powers a center console outlets) and slid the fuse and "plug" into the slot from the front.

On the stock power drivers seat you have to put the control switch in front and above the seat control. There is a hole in the seat frame directly behind this point that allows you to feed the control wires to the underside of the seat. Also, there is a vehicle ground just behind the shift stalk that you can secure the black ground line.

I now have dual power lumbar supports.
 
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